Yes, in my case I have to avail of unskilled labor so it's an important factor for me. You're right that for most expats it would be irrelevant.Unskilled wages apply for the COL of unskilled wage earners in the local economy. Expats depend mostly on foreign income .
Numbeo cost comparison Madrid/BA says that Life in Argentina is 21,8 % cheaper than Madrid. Their numbers are way outdated today Argentina is more expensive. See the Numbeo Cost comparison figures for reference only. Excludes rent.
Amazing that Argentina is more expensive than Spain despite much lower wages. Must be tough for people.